lhm leak

[white exec]

If anyone needs access to a vast range of O-rings (including Viton type for LHM use), this supplier has been used by many of us for some time now:
https://www.polymax.co.uk/
They're in Bordon, Hampshire, and usually provide immediate dispatch ex-stock.

[xantia_v6]

I followed advise and ordered 2.5mm, as mentioned above.
I'm guessing that whole operation need to be done after complete system depressurising (car suspension on low setting and release pressure - bolt beside acc sphere in front) ?

You need to depressurise the regulator (the bolt near the acc sphere), but there is no real need to depressurise the suspension, as it is isolated by the anti-sink valves.

As the pump is lower than the tank, you need to do something to stop the LHM from siphoning out of the tank while you have the outlet valve removed from the pump.

[Pshemsky]

Hi Guys. Still waiting for my o-rings, but meanwhile I would like to ask about something else related to LHM leaks.
First of all I had a situation where after few days I can find a lhm poodle on top of the tank - every citroen which I had before had exactly same problem. Is it common thing ? Should I worry about it ?

And second question.
Few minutes after engine wa started I can spot loads tiny air bubbles in a tank. Is this the air suck in through that leek which I'm trying to sort out or is there another issue somewhere else ?

Thanks for help.

[GiveMeABreak]

Well it will be related to air in the system and is better out than in of course. You need to find and seal the leak first as this is likely to be where it is entering the system.

[Hell Razor5543]

I would check the LHM level first. Raise the car to full height, and then see if the ORANGE disk is between the two red rings (NOT the BRASS disk). If the orange disk is between the rings the levels are OK. However, if it is below the lower ring it would be possible air is being drawn into the system (which could account for the bubbles).

[white exec]

Hi Prem,

Yes check the reservoir level as described. You can check that the level (float) device is working properly by unplugging it, and rotating it about 90deg, and lifting it out. You should be able to see and check full movement of the float and indicator.

One of the functions of the LHM reservoir is to de-aerate the fluid returning to it, and this is done by the two nylon mesh filters, which break up bubbles. The acid test is whether fluid with air still in it is being taken into the hydraulic pump. If it isn't, that's good; use a length of clear plastic tube inserted into the reservoir exit (pump supply) pipe to check.

In good condition, and with level correct (you can overfill by a litre without a problem, but not underfill), I don't normally see bubbles in tank LHM at all. So if they're there (and they should only be microscopic ones, if the large return filter is doing its job (no holes in it, and correctly fitted), then very aerated fluid might be being returned from the system.

The poodle (where's our cartoonist when you need him?) on top of the tank, is, as you say, not uncommon; I've had that too. Cause can be an old and poorly fitting large rubber seal on the top (still a available new), or else a leak from one of the return pipes.

[xantia_v6]

On a Xantia, the LHM tank gets distorted by the pressure of the spring clip which holds the top on, causing the sealing face to become saddle-shaped, so that for some of the circumference there is no pressure on the seal, and they nearly always leak.

I have had some success with cleaning the seal and tank top then applying a layer of oil-proof silicone sealant between the tank body and the seal (while not applying sealant between the seal and the lid).